Question: Simplify the following expression: $z = \dfrac{9}{6a - 5} \div \dfrac{2}{4a}$
Dividing by an expression is the same as multiplying by its inverse. $z = \dfrac{9}{6a - 5} \times \dfrac{4a}{2}$ When multiplying fractions, we multiply the numerators and the denominators. $z = \dfrac{ 9 \times 4a } { (6a - 5) \times 2}$ $z = \dfrac{36a}{12a - 10}$ Simplify: $z = \dfrac{18a}{6a - 5}$